diff --git a/tests/ref/basic.list b/tests/ref/basic.list
index 67056c84a9c..5cea73147ea 100644
--- a/tests/ref/basic.list
+++ b/tests/ref/basic.list
@@ -11,7 +11,6 @@ fragment=top != ../html/acid2.html acid2_ref.html
 
 == acid2_noscroll.html acid2_ref_broken.html
 flaky_cpu == append_style_a.html append_style_b.html
-prefs:"layout.flex.enabled" == flex_row_direction.html flex_row_direction_ref.html
 == floated_negative_margins_a.html floated_negative_margins_ref.html
 == font_size.html font_size_ref.html
 # `?` and `#` in the name is a test for https://github.com/servo/servo/issues/3340
diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index 9aa1de97736..71a4bf1cfaa 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -1295,6 +1295,18 @@
             "url": "/_mozilla/css/flex_nochild.html"
           }
         ],
+        "css/flex_row_direction.html": [
+          {
+            "path": "css/flex_row_direction.html",
+            "references": [
+              [
+                "/_mozilla/css/flex_row_direction_ref.html",
+                "=="
+              ]
+            ],
+            "url": "/_mozilla/css/flex_row_direction.html"
+          }
+        ],
         "css/float_clearance_a.html": [
           {
             "path": "css/float_clearance_a.html",
@@ -6132,6 +6144,18 @@
           "url": "/_mozilla/css/flex_nochild.html"
         }
       ],
+      "css/flex_row_direction.html": [
+        {
+          "path": "css/flex_row_direction.html",
+          "references": [
+            [
+              "/_mozilla/css/flex_row_direction_ref.html",
+              "=="
+            ]
+          ],
+          "url": "/_mozilla/css/flex_row_direction.html"
+        }
+      ],
       "css/float_clearance_a.html": [
         {
           "path": "css/float_clearance_a.html",
diff --git a/tests/ref/flex_row_direction.html b/tests/wpt/mozilla/tests/css/flex_row_direction.html
similarity index 93%
rename from tests/ref/flex_row_direction.html
rename to tests/wpt/mozilla/tests/css/flex_row_direction.html
index 68689e5eca9..b2ec3650905 100644
--- a/tests/ref/flex_row_direction.html
+++ b/tests/wpt/mozilla/tests/css/flex_row_direction.html
@@ -5,6 +5,7 @@
   <title>CSS Test: flex container should layout flex items horizontally</title>
   <link rel="author" title="Kyle Zentner" href="mailto:zentner.kyle@gmail.com">
   <link rel="help" href="https://drafts.csswg.org/css-flexbox/">
+  <link rel=match href=flex_row_direction_ref.html>
   <style>
     body {
       margin: 0;
diff --git a/tests/ref/flex_row_direction_ref.html b/tests/wpt/mozilla/tests/css/flex_row_direction_ref.html
similarity index 100%
rename from tests/ref/flex_row_direction_ref.html
rename to tests/wpt/mozilla/tests/css/flex_row_direction_ref.html